How to filter on multiple values in a drop-down menu?

If I have a column with values A~F and I want to use a filter in the drop down style, is there a way to make it so I can choose 2 values like A OR B. And all records with A or B get filtered.

Unfortunately there is no multiselect filter in the dhtmlxGrid.
You may try to use the filterBy method:
docs.dhtmlx.com/grid__filtering. … cfiltering
or create your own custom filter with the required logic.