Average workdays spent by Time filter

Hi EazyBi Team,

I got stuck at an issue, Can you please check the below at your convenience and do the needful.

Attached the image , The intention is to have data on the average workdays spent on the issue by time filter.
I have made ‘time’ as common filter and filtered issues by 2021 but I see issues coming even from 2018 ( May be one of the transition state for the issue is in 2021) but I would like to filter the resultset only to have the issues created after the selected ‘Time’ filter.

Please let me know if the above makes sense.