Not counting re-entries of festive songs:
-Michael Jackson 5 decades (70s, 80s, 90s, 00s, 10s)
10s:
2014 Love Never Felt So Good #9 (with Justin Timberlake)
2014 Slave To Rhytmn #45
2014 Billie Jean #14
2018 Don't Matter To Me #9 (with Drake)
-Paul McCartney 5 decades (70s, 80s, 90s, 00s, 10s)
10s:
2014 Only One #35 (with Kanye West)
2015 FourFiveSeconds #4 (with Rihanna & Kanye West)
2015 All Day #15 (with Kanye West)
-Elton John 5 decades (70s, 80s, 90s, 00s, 20s)
20s:
2021 Cold Heart #7 (with Dua Lipa)
2021 One Of Me #88 (with Lil Nas X)
2021 Merry Christmas #42 (with Ed Sheeran)
2022 Hold My Closer #6 (with Britney Spears)
(All have 6 decades if you consider re-entries of festive songs)
Obviously there are more artists, especially if you consider the re-entries of Christmas songs but I came to mind these 3 artists because I think that together with Madonna they are the only ones that had collaborations with current artists that entered the top 50 of the HOT 100.