Query to get current column based on date range
Assuming that tVehicle.BranchId contains Branch where the vehicle is currently at and branchId of branch B is 2 this should do the trick
DECLARE @branchId int= 2;
DECLARE @availableDate date= '2020-12-09';

SELECT tv.*
FROM tVehicle tv
WHERE tv.BranchId=@branch
AND NOT EXISTS(SELECT 1 FROM tBooking tb WHERE tb.VehicleId=tv.VehicleId AND @availableDate BETWEEN tb.StartDate AND tb.EndDate);