The ambiguity arises because you have one sentence doing three jobs.
It is telling us which city Jessica lives in, where that city is, and what the unemployment rate is.
The simple fix is to split the sentence, repeating "Halifax" Jessica lives in the city of Halifax, the capital of the province of Nova Scotia.
In Halifax, the unemployment rate is five percent.
Jessica lives in the city of Halifax, where the unemployment rate is five percent.
(do you need to say that Halifax is in Nova Scotia?)
Another way is to indicate a context in other sentences: Jessica lives in the city of Halifax, the capital of the province of Nova Scotia, where the unemployment rate is five percent.
This compares well with other Canadian cities.
In Ontario, the rate is ten percent.
However in the rest of Nova Scotia the unemployment rate is only two percent...
ell.stackexchange.com/users/24231/James K
Halifax has an unemployment rate of 5%.
Although the original sentence could be parsed as using parenthetical commas, it could also be parsed as having each comma functioning to have what comes after it modifying what comes before it.
To make it clear that it's actually parenthetical information, use actual parentheses:
Jessica lives in the city of Halifax (the capital of the province of Nova Scotia) where the unemployment rate is 5 percent.
Here, there is no way of misinterpreting the fact that it's Halifax with the unemployment rate.
Nova Scotia has an unemployment rate of 5%.
On the other hand, if you wanted to say that it's Nova Scotia with the unemployment rate, remove the second comma and, thereby, any indication of parenthetical information.
Also, rephrase the sentence slightly: Jessica lives in the city of Halifax, the capital of Nova Scotia where the provincial unemployment rate is 5 percent.
Now, without the second comma, everything after the first comma modifies what came before it.
Also, by writing provincial unemployment rate , it's impossible to mistake it as referring to Halifax.
The use of provincial also makes it clear that Nova Scotia is a province.
ell.stackexchange.com/users/73781/Jason Bassford
I think the simple answer is, Don't be afraid to break up the sentence.
I'd write, "Jessica lives in Halifax, the capital of Nova Scotia.
The unemployment rate in Halifax is 5%."
We have a fair number of questions on this site about "how do I eliminate the ambiguity without adding more words".
Very often the answer is, "There is no other way.
You have to add more words."
ell.stackexchange.com/users/803/Jay
Reorder the clauses so there is no ambiguity.
The subordinate clauses can only refer to things mentioned earlier in the sentence, so: Jessica lives in Halifax, a city with an unemployment rate of five percent and the capital of the province of Nova Scotia.
You might want to replace "and" by "which is", but IMO the grammatical arguments either way are mostly pedantry.
ell.stackexchange.com/users/19004/alephzero
I really like alephzero's answer, because I find long mid-sentence parenthetical (or dashed) clauses not really compatible with direct journalistic or business writing, which is the style that is perhaps being aimed for here.
I'd consider:
J lives in Nova Scotia's capital, Halifax, a city with a 5% unemployment rate.
or if you feel the audience needs to be reminded that NS is a province: J lives in the capital of the province of Nova Scotia, Halifax, a city with a 5% unemployment rate.
and if the opposite sense is intended: J lives in Halifax, capital of Nova Scotia, where the provincial unemployment rate is 5%.
ell.stackexchange.com/users/46904/CCTO
Use of parentheses will easily clarify this: Jessica lives in the city of Halifax (capital of the province of Nova Scotia), where the unemployment rate is 5 percent.
The focus, and hence the unemployment rate, remains with Halifax.
ell.stackexchange.com/users/48224/Davo
Halifax, the capital of Nova Scotia has an unemployment rate of 5 percent.
It is here that Jessica lives.
I am working on the premise that you would not list Halifax' unemployment rate if you did not intend to put it into some relation to Jessica's living situation, so this expository style gives you a good starting place for creating the context you want to establish for Jessica.
Instead of "lives", something more specific like "moved in order to work at Wooly's, a company specialising in mirror symmetrical pairs of socks" can be used in order to tie this into whatever comes next in a cohesive manner.
ell.stackexchange.com/users/None/
Another option: turn it inside out.
In Halifax, Nova Scotia, where Jessica lives, the unemployment rate is 5%.
ell.stackexchange.com/users/18020/Majenko
Jessica lives in Nova Scotia--specifically, in Halifax, where the unemployment rate is 5%.
As for the original version, this is a worthwhile sentence only if the 5% unemployment rate is important to/for Jessica, and that very soon now we'll get to the point.
ell.stackexchange.com/users/99642/Bruce E Trumbo
The sentence here is quite confusing. I wrote this.   Jessica lives in the city of Halifax, the capital of the province of Nova Scotia, where the unemployment rate is 5 percent.   A fellow reader is confused:  Is the writer talking about the unemployment rate of Halifax or Nova Scotia?  I want to say the rate in Halifax is 5 percent. How do I establish clarity without breaking the sentence in two and repeating "Halifax"?
How to remove ambiguity: "... lives in the city of H, the capital of the province of NS, WHERE the unemployment rate is ..."?
ell.stackexchange.com
<sentence-construction><sentence-choice>
ell.stackexchange.com/questions/220971
ell.stackexchange.com/users/77766/AIQ
 Use of parentheses will easily clarify this:   Jessica lives in the city of Halifax (capital of the province of Nova Scotia), where the unemployment rate is 5 percent.    The solution is to break up the sentence and reorder the clauses to remove any ambiguity.
The solution is to break up the sentence and reorder the clauses to remove any ambiguity.