If you follow the function pointer to where the actual function's address is in your first binary, you should see something similar to this.

00870808 09 00 00 80 addr <EXTERNAL>::Function_Something

Right click the operand (the <EXTERNAL>... part) and select Edit External Location. A new dialog window will pop up.

In this window, click the Edit button next to the Path field and select your .so file.

If you follow the function pointer to where the actual function's address is in your first binary, you should see something similar to this.

00870808 09 00 00 80     addr      <EXTERNAL>::Function_Something

Right click the operand (the <EXTERNAL>... part) and select 'Edit External Location'. A new dialog window will pop up.

In this window, click the 'Edit' button next to the 'Path' field and select your .so file.