You made it to the top 3.
Maybe even #1 in the SERP.
Analyze what you're missing on that same topic
Use Ahrefs & enter your URL
Set the results for EXACT URL
Filter for positions 20-50
See what you get
Those keywords are probably ones that you won't rank for without another post.
Review those keywords and see if another, related topic emerges. Check the SERPs and then write another post.