Compare records on same table to show differents

[Anonymous]

Hello,

i am trying to understand if the below is possible.

the goal is that the user will have the capabilities to choose same 'parent' and 2 time periods and the Object will show them the unique 'Son' for each of the tables.

*table is over 1.5M records

*no use of Macros/Subs

Parent	Son	time period
A	1	1
A	2	1
A	3	1
A	4	1
A	1	2
A	2	2
A	3	2
A	5	2
A	1	3
A	2	3
A	5	3
A	6	3
B	2	1
B	10	1

Thanks!

[Anonymous]

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