【Seek Help】 How to enable the Two Filter's Dropdown value based on each other?

Hi Expert, 

We are building a report to show the headcount information. The report has following 4 tables. 

Table 1 Active Emploee Table

Table 2 Terminated Employee Table

Table 3 Location Lists

Table 4 Department List

We have two filters in the report which are Location and Department. (We use the value from Table 3 for the Location Filter, and Table 4 for the Department Filter). It enables us to filter the value in both Table 1 and 2. 

The question we seek your help is:

How should we build the relationship between Table 3 and Table 4 to enable its drop down shows the value based on each other?

For example, if we choose "A" in the Department Filter, the dorp down for Location Filter just show A's location which are "Hong Kong", "Paris", “New York" and "Singapore". 

Same for the other way around, if the user choose "Singapore" in the location filter, the drop down for Department Filter should just show Singapore's Department which are "A" and "C".

Many thanks!

Best regards,

Tom