Using BEX Query Designer conneted on ECC Hana Studio

Hi Experts,

We have developed a calculation view using SQL Script on ECC and we are trying to create a query on BEX Query Designer, but we are facing some issues.

Some key figures doesn´t appear on query designer and there are some limitations to use variables in the fields.

Anybody has connected a hana model direct in BEX Query Designer ? What can be done to work around the limitations ?

I will appreciate some documentation about it ?

Thanks