Unable to use Aggregation on CDT fields with many-to-many relationship.

first create the mapping table on both campaigns and channels 

then Create a query rule to fetch the required data from campaigns associated with channels 

a!queryEntity(
entity: cons!YOUR_CAMPAIGN_ENTITY,
filters: a!queryFilter(
field: "id",
operator: "IN",
value: ri!campaignIds
),
query: a!query(
pagingInfo: a!pagingInfo(startIndex: 1, batchSize: 100),
selection: a!querySelection(columns: {"id", "campaignName", "channel.id", "channel.channelName"}),
filters: a!queryFilter(
field: "channel.id",
operator: "IS NOT NULL",
value: ri!channelId
)
)
)

Once you retrieve the campaigns and associated channels, you can group the campaigns by their channel

i hope this will use 

Thanks for your reply.

We already have a mapping table between campaign and marketing channel to store the many to many relationship.

Even filtering on channel value is not working.

Code:

a!localVariables(
local!data:
a!queryEntity(
entity: cons!MSS_ENTITY_CAMPAIGN_REQUEST,
query: a!query(
logicalExpression: a!queryLogicalExpression(
operator: "AND",
filters: {
a!queryFilter(
field: "marketingChannels.value",
operator: "in",
value: ri!channel
)
},
ignoreFiltersWithEmptyValues: true
),
pagingInfo: ri!pagingInfo
),
fetchTotalCount: true
),
local!data
)

Error: