In AppMon, we could have chart the portion or response times of all DB components that belong to an application, by just using business transactions for example. This was needed in case of users who have migrated from other tools such as newRelic or AppD and were using similar charts.
As Dynatrace does not have the BT capability in that sense and as the PurePath are more modular How would you suggest to create such chart (taking into account that not all databases are directly linked to the first level or the service flow).
I think the best way is to tag entities to match the same group (in appmon application) and than you will be able to create custom charts filtered by this tag. This should give you what you need.