Hi,
Well, tough query, but might be possible via some custom CSS.
Try this:
fieldset.asp_filter_tax.asp_filter_tax_category {
width: 100% !important;
min-width: 0% !important;
max-width: 100% !important;
}
fieldset.asp_filter_tax.asp_filter_tax_category .asp_simplebar-content {
display: flex;
flex-wrap: wrap;
}
fieldset.asp_filter_tax.asp_filter_tax_category .asp_simplebar-content>.asp_option_cat {
min-width: 40%;
}
Apply this code to your theme custom CSS field (if it supports it) or use the custom CSS field on the search plugin back-end.