I create a tab group to display tabs in dual mode (right/bottom side) and I create a button Go TABGROUPLOAD="MyGroup" to display it.
But when I click button in single mode lister, tabs are always open in right side.
How I can always open my tabs in bottom?
I notice that if i open dual horizontal mode then close. If i run command, tabs are open in bottom.
So maybe that dual mode position could be saved in default lister?
The vertical/horizontal layout is part of the lister and can be saved in the Default Lister, or Layouts, or Styles.
You could also have a command which switched on dual-horizontal and then loaded the tab group, if you don't want it as your default and only want it to happen when clicking that button to load that particular tab group.
When the new version is out, you'll be able to switch to Dual Horizontal, then turn off Dual entirely, and save the Default Lister (or a named layout).
When you then re-load that lister or layout, it will use Dual Horizontal mode by when anything opens a the second file display (e.g. folder tab groups in your example). (Unless the thing opening the second file display explicitly overrides the orientation, of course.)