How does filter work in Tempo Tasks report? Any examples or tutorial will be app

How does filter work in Tempo Tasks report? Any examples or tutorial will be appreciated. The current filter is not working.
Below is the sample code
=load(
local!pi: a!pagingInfo(startIndex: 1, batchSize: 20),
local!categoryFilter: 1,
with(
local!ds: rule!epGetDataSubset(pagingInfo: local!pi,filters: if(
isnull(local!categoryFilter),
{},
{field:7, operator: "EQUAL", value: local!categoryFilter-1}
)),
a!dashboardLayout(
firstColumnContents: {
a!dropdownFieldByIndex(
label: "Category Filter",
choiceLabels: {"All", "BMW", "Audi", "Merc"},
value: local!categoryFilter,
saveInto: {
local!categoryFilter,
local!pi << rule!updatePagingInfo << rule!returnFirstInput(local!pi, _)
}
),
a!gridField(
label: "My Tasks",
instructions: "A list of all tasks for the current user.",
columns: rule!epActiveTasksReport_Columns(local!ds),
value: local...

OriginalPostID-115506

OriginalPostID-115506