PowerBI Report(Dax)

Odada , For % of total refer , assuming you already have measure submission

submission% = divide([submission], calculate([submission], allselected()) )

or

submission% = divide([submission], calculate([submission], removefilters(Table[Zone] )) )

Percent of Total and Percent of SubTotal https://www.youtube.com/watch?v=6jTildcV2ho
https://www.youtube.com/watch?v=cN8AO3_vmlY&t=24270s

You can use time intelligence and date table for MOM

MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD('Date'[Date]))
last MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD(dateadd('Date'[Date],-1,MONTH)))
last month Sales = CALCULATE(SUM(Sales[Sales Amount]),previousmonth('Date'[Date]))
MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD('Date'[Date]))

Time Intelligence, Part of learn Power BI https://youtu.be/cN8AO3_vmlY?t=27510
Time Intelligence, DATESMTD, DATESQTD, DATESYTD, Week On Week, Week Till Date, Custom Period on Period,
Custom Period till date: https://youtu.be/aU2aKbnHuWs&t=145s

For 3rd you can use Index or topn

TOPN: https://youtu.be/QIVEFp-QiOk
TOPN with Numeric Parameter -https://youtu.be/cN8AO3_vmlY?t=26448

Power BI Index function: Top/Bottom Performer by name and value- https://youtu.be/HPhzzCwe10U