Exclude row from filtering/search

Is it possible to keep specific rows always visible in a search? I have 1 table with different categories:

Category 1
– sub 1
– sub 2
– sub 3
Category 2
– sub 4
– sub 5
– sub 6
Category 3
– sub 3
– sub 7
– sub 8

Search on “Sub 3” result:

Category 1 <— Is a row in the table but should stay visible when result in this part
– sub 3
Category 3 <— Is a row in the table but should stay visible when result in this part
– sub 3