Columns in submenu

I need to create 2 columns or even 3 to the submenu

I used this code

.bd-menu-10 {display:inline-block; width:500px !important;}
.bd-menuitem-25 {width:50% !important;}
.bd-menuitem-25 a:hover{color:#FFFFFF;}
.bd-menuitem-25:nth-child(odd){float:right;}

With

.bd-menuitem-25:nth-child(even){float:right;}

I have a "hole" in the submenu (see picture) to the left

and with

.bd-menuitem-25:nth-child(odd){float:right;}

I have a "hole" at the top

Can you help me so that the "hole" is at the bottom right, please?

Or any other code for columns in the submenu