When you click on the buyer, because the buyer corresponds to the database, you can get the primary key (usually id) corresponding to the buyer.

Use the primary key to query in the database, find other information of the buyer and display it.

This code is still relatively long (between 500~ 1000 lines), so I suggest you implement it according to the above ideas. There is little chance for others to provide you with complete code here, unless it is an algorithm problem.