Suppose you want to get Baseline Start Date of a task for multiple baselines. This query can be used for the same:
select object_type,object_id, start_date, finish_date
from prj_baseline_details
where baseline_id = (select ID from prj_baselines where object_type = 'PROJECT' and name = 'Abhisek_Baseline1' <Your baseline Name> and project_id = 5002073 <your project ID> )
and object_type = 'TASK'
Hope that helps you to get an idea.