title: Use Field_A value to find records based on a modified version of Field_A value on the same field
body: <p>I have the following table, and I want to get the desired result set, based on :</p>
  
  <ol>
  <li>Replace CS with C1 in "TICKER" and Replace CG with C2 in "TICKER". </li>
  <li>Use above Ticker to find an exact match in TICKER field in the same table.</li>
  <li>If there is a match, return the pair of records.</li>
  </ol>
  
  <p>Existing Table:</p>
  
  <pre>
  TICKER | EXCHANGE | COUNTRY
  -------+----------+--------
  123 CS | HKE      | HK      
  123 C1 | SGX      | SG
  124 CG | LSE      | GB
  124 C2 | NYE      | US
  125 CS | NAS      | US
  125 C1 | SGX      | SG
  126 C1 | KUL      | MY
  </pre>   
  
  <p>Desired result set:</p>
  
  <pre>
  TICKER | EXCHANGE | COUNTRY
  -------+----------+--------
  123 CS | HKE      | HK     
  123 C1 | SGX      | SG
  124 CG | LSE      | GB
  124 C2 | NYE      | US
  125 CS | NAS      | US
  125 C1 | SGX      | SG
  </pre>   
  
  <p>Appreciate your help on how to use the "C1/C2 ticker" to find an exact match so as to return the pair ? </p>
  
  <p>thanks </p>