How can I scan for a positive divergence on the 3, 35, 5 MACD (Exponential) using a weekly chart, and on last 10 bars?

It would depend on your particular unambiguous objective definition of divergence, but let's start with a fairly simple way to search for a divergence between Price and MACD over the most recent 10-bars.

Click on Price and select Create Condition. Then select Moving Up from the Condition drop-down menu (Net, % or Smart would do, but I'd start with Smart). Then set the Period of the Condition to the number of bars over which you wish to check for a divergence (in this case, 10).

Indicators, Sorting & Scanning

Then do the same thing with the MACD indicator, but choose Moving Down instead of Moving Up.

You can then add both the Conditions to the same Scan. Checking for a divergence where Price was Moving Down and MACD was Moving Up would just be a matter of switching around how you created the Conditions.