I can see that you are using EMAXXBH app on Eikon Desktop.
The displaying data on the app cannot be access using API.
However, whether the raw data is accessible by API or not, please raise this query to Refinitiv Helpdesk at https://my.refinitiv.com/ to check if the raw data can be retrieved using TR functions on Eikon Excel and on which fields.
If the data is accessible, the helpdesk would be able to also give you the field names.
Then you can use get_data to retrieve the same information.
You cannot use Eikon Data APIs(Python) to screen for funds.
You can use Fund Screener app on Eikon Desktop
1. Type FSCREEN in Eikon Search bar and press enter
2. Add any search criteria, in your case, fund manager name
3. Click on "Preview Number Of Assets" then click on "Generate Report"
4. You will see a list of FUND RIC
5. You can export this list to csv if needed
Once you have a list of RIC, you can use this API call to get holding RIC
In this example, I am using LP68387770 as sample RIC code.
data,e = ek.get_data("LP68387770", ["TR.FundHoldingRIC(StartNum=0,EndNum=2000)", "TR.FundNumberOfShares(StartNum=0,EndNum=2000)", "TR.FundPercentageOfFundAssets(StartNum=0,EndNum=2000)"])
Here is sample output: