How to use multiple sliding_window_counts in a single query

ankasani , you can try something like this 

let Start = startofday(ago(60d));
let End = startofday(now());
let MAUwindow=30d; //MAU 30d, WAU 7d, DAU 1d
let WAUwindow=7d;
let DAUwindow=1d;
let bin = 1d;
let filteredEvents= materialize (customEvents
| where timestamp >= Start and timestamp <= End
| project user_Id, timestamp);
let MAUcounts=filteredEvents
| evaluate sliding_window_counts(user_Id, timestamp, Start, End, MAUwindow, bin)
| project timestamp, mau=Dcount;
let WAUcounts=filteredEvents
| evaluate sliding_window_counts(user_Id, timestamp, Start, End, WAUwindow, bin)
| project timestamp, wau=Dcount;
let DAUcounts=filteredEvents
| evaluate sliding_window_counts(user_Id, timestamp, Start, End, DAUwindow, bin)
| project timestamp, dau=Dcount;
MAUcounts
| join kind=inner WAUcounts on timestamp
| join kind=inner DAUcounts on timestamp
| project timestamp, mau, wau, dau
| render timechart with (ysplit=panels)