Need help understanding ground leases
Can’t seem to wrap my head around this. Any clarity is greatly appreciated. 

Here is the simplified deal:
Owner A is planning to develop two mixed-use buildings. One building will be an office building. The other will be an apartment building. Both will have ground floor retail. 

Owner A owns the land. Owner A will retain all ownership of the office and apartments and operate them. They will not retain ownership of the retail. 

Owner A decides to set up the transaction by creating a ground lease on the retail portions. Buyer B likes the deal and agrees to develop the retail. 

So... now what? 

I’m confused on the following:
1. What role does Buyer B play in this stage of the transaction as it pertains to Owner A? What additional roles, if any, could Buyer B play in this scenario? 
2. Are the terms operator and manager interchangeable? If not, I am seeking clarity on the differences. 
3. If Buyer B “sub ground leases” the retail portion to individual tenants, what implications does this have on all parties involved? 
4. How does this third channel of interest effect underwriting assumptions for each party? If this answer is too long to discuss, then I’d be most interested in hearing this answer as it pertains to Buyer B. 

Apologies for the vagueness here but seeking any clarity on transaction structure for ground leases when multiple parties are involved, what implications this has on underwriting assumptions, and some discussion points I can think about as I fall asleep knowing I’m a confused dev analyst who wishes they did not leave investment sales (haha). 

Thanks guys.
[{"id": "fmz5hfu", "text": "This isn\u2019t a ground lease. This is a commercial condominium. \n\nA typical ground lease works like this: \n\nPerson A owns a piece of land, let\u2019s say adjacent to a Target. \n\nPerson B wants desirable land to build on, let\u2019s say to build an In N Out burger joint. \n\nPerson A agrees to lease the piece of land for a designated amount, usually on a long term lease. Person B builds the In N Out burger joint, and operates accordingly.", "replies": [], "depth": 1}]