Capital gains on retransfer of shares originally received th

It is understood that if an individual B receives shares through transfer of shares from  a relative A  (by way of transfer from one demat account to another),   say as a gift, then Capital Gains  liability on such shares shall arise only if and when they are sold by the recipient B and the date of purchase by original holder A shall be considered as the date of purchase for the purpose of calculating period of holding. However,  in case this individual B who has originally received these shares through transfer, decides to transfer them further to the original holder A / other holder C, what shall be the capital gains liability of B or C, arising from such retransfer.