Problem multi filter based on different condition column value excel.

[Krypt]

Hello everyone,

Excel 365 Apps for enterprise

I am using a formula to filter column O when a value is used when selecting it in a data validation column B.
Formula : =FILTER(Tel,COUNTIF(B7:B21,Tel)=0) is in cell P8.
I would like to modify this formula when in column H a certain value is show ("Return") that the value used in column B becomes visible back in column P (unfilter column P).

Thanks in advance for the big help.

Kind regards
Krypt

 

[Krypt]

Sorry forgot to specify,
When the value return in column P we can use de value back in the data validation, also the used value in column B must not disappear.