How do i bind data from Database to dropdown A by selcting another dropdown B

Hi please i want to diplay the correct data in dropdown by selecting dropdown B, example i have two dropdown on page dropdown A is Wears and dropdown B showsing the examples that dropdown A will select

Dropdown A

Wears,Funitures

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Dropdown B Cloths, Chairs

If wears is selected it will show on dropdown B Cloths

If Funitures is selected it will show ON dropdown B

Chairs

Database table Category A

ID 1 Username mic33 Category wears

Database table Category B

ID 1 Username mic33 Category Cloths