to achieve your task
make a SerachHelperEntity in Your Domain Model with attribute Visible boolean type by default make (/leave) it false
make SerachHelperEntity and Region many to one [*-1] association and associate it with Test_center and Tables Entity with one to one [1-1] associations
see in screenshot
then then go to page where you want to show your data and in dataview select datasouce to SearchHelperEntity
then inside data view take layout grid of 6,6
then in first column put a refrence selector and select attribut to TableName by association
then in second column of layout grid put another refrence selector and select attribute to RegionName By association
Now Select Visiblity COndion of second Refrence Selector
After Click edit choose based on attribute Value choose visible attribute on true
Then again go to First Refrence Selector and edit its onchnage event and call a microflow
and make your microflow in which
firstly add a string parameter
and in its value TableName like below (make sure association name may be vary so path will be change according to association Name)
$SearchHelperEntity/MyFirstModule.Tables_SearchHelperEntity/MyFirstModule.Tables/Table_name
after add parameter add a decision and check Table_name attribute value is Location or Not
in Expression of decision
$SearchHelperEntity/MyFirstModule.Tables_SearchHelperEntity/MyFirstModule.Tables/Table_name='Location'
on true condition take and change object Activity and and in SerachHelperEntity Set Visible to true
and Make Sure Commit yes and Refrence in client should be yes
same on false condition change object of SearchHelperEntity and make Visible member to false
after it go back to your page where you are showing your data and put a list or data grid after both refrence selectors and select data souce a microflow and Create New Microflow for example OCH_Region_ListGet , and make sure refresh in data grid should be on in seconds
in data grid
now go to your newly created microflow and write OQL to fetch your test_center data
i hope you know how to use OQL (for OQL download OQl and community commons from marketplace and if any error occurs remove pages from atlas view pages that giving errors) in mendix if you are not new in mendix
so in microflow
firstly add a string parameter
and put value to RegionName ( in value of parameter ) = $SearchHelperEntity/MyFirstModule.SearchHelperEntity_Region/MyFirstModule.Region/RegionName
then Execute OQL
'SELECT test.Name as Name ,test.Code as Code,test.Active as Active
FROM MyFirstModule.Region as region
INNER JOIN region/MyFirstModule.Test_Center_Region/MyFirstModule.Test_Center as test
WHERE region/RegionName =$RegionName'
and set another parameter according to picture
and in end Event return that list
now go to your data grid and click on a colum and by drag and drop from connector tab set all column attributes
now your all configuration done
i hope it will help you