this is the same with "Reentry Finder" indicator plus the filter of midbb, if price be above middle bollinger band, it will alert for buy only and if it be below the middle bollinger band it will alert for sell only. here the link to the previous version:
https://www.mql5.com/en/market/product/33843

inputs:

Pip_distance: the acceptable distance between Moving Average and price to get alert
timeframe: in witch timeframe it will looking for the setup

"please be aware that alert() function of mql, does not work on the strategy tester, so trying this indicator on demo tester will result in nothing"
feel free to text me if you need any other modifications to this indicator.

there is also "Reentry Dashboard" indicator with alerting, you can check it here:
https://www.mql5.com/en/market/product/40080

and an ultimate BBMA dashboard for the all BBMAs setups and signals:

https://www.mql5.com/en/market/product/41366