I have the below tables:
For any new doctor appointment bookings, I like to show only the available slots for the particular hospital selected by the user on that particular day. Below is the filter I wrote, but this is not returning any slot. Below are the screenshots. Can you please help.
Moderator note: Edited out personal information from image.
Hi @Gout-436f 
Happy to help!
For this, you'll want to have a table set up with time slots that can be filtered out by day and booking status:
Now in your app, for the time slot data cell, set it to a rowlink and filter for only the available time slots of the selected date.
The FILTER formula in my example is:
=FILTER(TimeSlots,"TimeSlots[Date]=$[Date] AND TimeSlots[Status]=%","Available")
This is how the app looks in action:
Hope this helps! Let us know if you have any other questions. 
Hi Alyssa. Shouldn't the TimeSlots table also have a "hospital" column?
Hi @Ayhan! Thanks for chiming in
Yes, you can add as many columns / criteria to match as needed, as you mentioned. (i.e. add a column of hospitals to the time slot table, then add the criteria to the FILTER formula with AND). This is how it looks:
