There is a table "table" with fields id, parentid, title
records:
id parentid title
1 0 audi
2 0 bmw
3 0 mersedes
4 1 A4
5 1 A8
6 3 S600
7 3 W220
how to do so when selecting records with parentid = 0 in one select, another updated and select it to display records with parentid = id
1 select: brand
2 select: model
if you select in the list of brand, the second select to renew the values that belong to that brand (by parentid)