Starting from the 2016R1 release, isCOBOL support the ACCORDION control using a specific style for the TAB-CONTROL.
This layout can be activated with the new style named ACCORDION, it is useful to groups some controls that will be visible only when selecting an item in the tab-control with the layout effect of "accordion" while clicking on the items.
03 Tb1-accordion tab-control
line 2 col 2 lines 17 cells size 68 cells
The image shows the final result with the ACCORDION style set on TAB-CONTROL.