Azure Monitor Metric Dimension Filter without Splitting

<!-- Please only use this template for submitting feature requests --> **Why is this needed**: When building a dashboard, I sometimes want to filter a metric based on a dimension with the startsWith operator or equals with multi-select, but I still want all results to be summed into a single time series. This is possible in the Azure Monitor UI of the Azure Portal by using the "Dimension Filter" option instead of "Dimension Splitting". **What would you like to be added**: I would like to be able to choose for each dimension of a Azure Monitor metrics query if I want the data to be summed into one time series or split into separate series. I inspected the network traffic of the Azure Monitor UI in the Azure Portal to see how they achieve this. Apparently there is a query parameter called `rollupby` for this purpose. An example request that returns the Metric for all SFTP transactions on a storage account could look like this: `/subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/resourceGroups/yyyy/providers/Microsoft.Storage/storageAccounts/wwww/providers/microsoft.Insights/metrics?timespan=2025-10-28T08:30:00.000Z/2025-10-29T08:45:00.000Z&interval=PT15M&metricnames=Transactions&aggregation=total&metricNamespace=microsoft.storage%2Fstorageaccounts&top=10&orderby=total desc&$filter=ApiName sw 'Sftp'&rollupby=ApiName&autoadjusttimegrain=true&validatedimensions=false&api-version=2019-07-01` I tried to achieve the same result using the *Series to rows*, *Group by* and *Partition by values* transformations but ran into problems because the name of the resulting series after the first transformation depends on the number of series merged, e.g. seriesToRows-A-A-A-A-A, which can change with the underlying data. This means that any further operations that needed to know the input series' name failed when I changed the time window. **Who is this feature for?** Users who want to build detailed dashboards using the Azure Monitor data source.