Dear all
I have a micro panel(No: of firms=3000 and no: of years=8). My variable of interest is Cashflows(unscaled) & I am interested in finding trend and cycle components of cashflows. Since it is obvious there will be gaps in Cashflows due to missing data, I am unable to use filtering methods like HP/BK. Below gives the ts report and due to gaps, I am unable to proceed.

Panel variable: id
Time variable: year
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Starting period = 2011
Ending period = 2018
Observations = 22256
Number of gaps = 5945
(Gap count includes panel changes).
In the above case, is there any way to do filtering rather than abandoning the study.