I am trying to filter several columns of a spreadsheet that contain specific
values on an OR basis, so I can't use the built in filters. I am using the
following function:

=IF(ISBLANK($A$1),"TRUE",(IF(OR(A3=$A$1,E3=$E$1,F3 =$F$1),TRUE,FALSE)))

I can then filter one column which is either true or false. This is great
provided the values I am searching for are exact which they are not, does
anyone know how I may alter this function to return true or false if the cell
"contains" a specific value.

Cheers