Got to thinking after posting, I gave you an answer, but didn't share any knowledge.

In the Data Sheet there is a section called 3.0 Memory Organization. On page 23, Table 3.3 shows where SFR are stored; both Bank# and Address#. You should be able to look at that Table and see PORTA located in BANK 0 at address 000Ch. Next row in BANK 1 you see TRISA at address 008Ch, but the same position within the BANK. Next you can see TRISA in the same position in BANK 2.

Using BANKSEL is a shortcut that allows the Compiler to find the proper BANK for you. In the Instruction Summary, Section 24, Table 24-3 lists the Assembly Instructions applicable to this PIC. Towards the bottom under the heading Literal Operations is the command MOVLB. If you know TRISA is in BANK 1 you can:

MOVLB 0x01

Page 272 shows the expanded explanation of MOVLB.

I hope this helps you better understand how the Banking system works (at least in the PIC family).