When your data table is kept external (in an SQL database), and when you try to add TIME columns on the X Axis or Category Axis of a visualization, you will find that time hierarchies are not available for such columns. See the screenshot below for an example.

But if the data table is imported into the analysis file, time hierarchies will show up. See the screenshot below for a comparison.

This behavior is by design. The only possible workaround to have a slider on the X Axis or Category Axis would be to manually create the hierarchy first from Insert > Hierarchy, and then select that new Hierarchy on your X Axis or Category Axis

The custom expression for a column with time hierarchy slider is something like below. Since "BinByDateTime" is not a supported function in SQL, manually typing in the same custom expression for an external data table will not work:

 BinByDateTime([DATE_JOINED],"Year.Quarter.Month",1) 

If a slider is not required, you can also use a custom expression like: 

 <Year([DATE_JOINED]) NEST Month([DATE_JOINED])>

Time Hierarchies Does Not Show on X Axis and Category Axis for External Data Tables

Doc: Working with In-Database Data

• https://docs.tibco.com/pub/sfire-analyst/7.11.0/doc/html/en-US/TIB_sfire-analyst_UsersGuide/data/data_working_with_in-database_data.htm