Select panel label > Editor > Edit Panels > Arrangement
Use to change the default panel arrangement and the margins separating the panels.
Rows and Columns
Automatic: Choose to accept the default panel arrangement.
Custom: Choose to change the panel arrangement.
Rows: Enter the number of rows in your custom panel layout.
Columns: Enter the number of columns in your custom panel layout.
Margins between panels: Choose to adjust the space between the panels, then enter a value from 0 to 0.25 in figure units.