May be try rest API call to dashboard definitions and see if Advanced XML related nodes like <module> <param> or <populatingSearch> are used. Since I have not used Advanced XML myself, I do not know whether there is something in metadata fields like root, eai:type, isDashboard will be same for Advanced XML and Simple XML or not. So you can check those as well. (Do remove search filter and table all fields to compare fields for regular Simple XML dashboards and Advanced XML).
| rest /servicesNS/-/-/data/ui/views
| search eai:data IN ("*<param>*","*<module>*","*<populatingSearch>*")
| table eai:acl.app title label
But what if I have 50 or more dashboards which are using Advanced XML. In this case, rewriting each dashboard manually is not an efficient one.
Please help me on the below: 1. If there are more number of dashboards which use Advanced XML, how to fix those with automation.
2. Also if I have an app which is created by own and it is using Advanced XML, then how can fix it. Do we need to modify anything from the backend? What are the files which need changes as part of this?