How to run dynamic query in oracle select?

Question

Oracle

I need something like this:

begin
    for group_level in (select * from group_level)
        loop
            execute immediate 'select :gosb from erp_trips' using group_level.gosb_id;
         end loop;
end;

Group_level is a table in which gosb_id is the name of the field to get from erp_trips (in this case 'GOSB')

The code is executed but the table is not displayed, what's the problem?