I need help writing an "IF" formula

Pedro_Rossie 

Here's a better solution, which involves a bit of reorganizing. This uses FILTER rather than IF, but accomplishes what you want because FILTER incorporates the criterion in itself.

Here's the formula: =FILTER(Table1,Table1[Priority]='Filtered Lists'!B1,"None")

First, to make a single formula work, you need to put those separate lists into a single database, going from 201 through 1102. It's always better to create single databases (tables) than to separate them as you had done.

Once that was done, the FILTER function readily works to select whatever category you want. Here's what the end result looks like for Priority=1. 

 And here it is for Priority = 2

By the way, you should not have posted that file--unless those names were fictitious. That's why I've changed all names to "MickeyMouse." I'd recommend you take down your original immediately.