Hi @Fathiyyah0 !
Great idea! Many hosts with larger properties are considering this option to maximize their listing. You basically create 2 listings; A "parent (the whole house-4bedrooms), and a "child" (3 Queen bedrooms). Several concepts to keep in mind:
Maximize Revenue - Larger Listing
You want to maximize revenue on the larger, 4bedroom listing, so many hosts only open up the "child" listing after their calendar has filled somewhat with the "parent." Some also only offer the "child" closer to check-in date, as the larger listing will book further out. This might not work for you, but something to consider.
Be Sure to Lock Out 4th Bedroom Not Being Used
You would need a reliable plan to be able to lock/unlock that 4th bedroom as appropriate. Clearly indicate in the "child listing" that the 4th bedroom is not available when they book it.
Sync Calendars
Be sure to sync calendars correctly.