Override QuickFilter mothod on Grid.ts file.

 protected getQuickFilters(): Serenity.QuickFilter<Serenity.Widget<any>, any>[] {

            // get quick filter list from base class, e.g. columns
            let filters = super.getQuickFilters();

            // get a reference to order row field names
            let fld = Bhaktyadi.BhaktMasterRow.Fields;

            let filter = Q.first(filters, x => x.field == fld.FirstName);
            filter.title = "First Name:";
            filter.handler = h => {
                // if filter is active, e.g. editor has some value
                if (h.active) {
                    h.request.Criteria = Serenity.Criteria.or(h.request.Criteria,
                        [[fld.FirstName], 'like',  h.value + '%']);
                }
            };


           filter = Q.first(filters, x => x.field == fld.MiddleName);
            filter.title = "Middel Name:";
            filter.handler = h => {
                // if filter is active, e.g. editor has some value
                if (h.active) {
                    h.request.Criteria = Serenity.Criteria.and(h.request.Criteria,
                        [[fld.MiddleName], 'like',  h.value + '%']);
                }
            };
            filter = Q.first(filters, x => x.field == fld.LastName);
            filter.title = "Last Name:";
            filter.handler = h => {
                // if filter is active, e.g. editor has some value
                if (h.active) {
                    h.request.Criteria = Serenity.Criteria.and(h.request.Criteria,
                        [[fld.LastName], 'like',  h.value + '%']);
                }
            };
            return filters;
        }