How to compare values in two columns in custom filters

[ayaroshenko]

Hey! 

I faced this issue, when I need to compare every value from one column with every value in the second column and filter the table.. Basically I have two columns with some values:

col1	col2
val1	vala
val2	valb
val3	valc
...	...

I need to compare: 

val1 with vala

val1 with valb

val1 with valc

val2 with vala

val2 with valb

and etc.

And I need to filter the table and leave only values, that are matching. 

I’d appreciate your help!