Hi All, How does filter work in Tempo Tasks report? Any examples or tutoria

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!pi,
saveInto: local!pi,
totalCount: local!ds.totalCount
)})
)
)

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!pi,
saveInto: local!pi,
totalCount: local!ds.totalCount
)})
)
)