C# - Proper Implementation Of Nested API Calls Using Connection Pool And Nested Transactions?

I need to know the best way to do the following. I have nested business level APIs (say level 1 & level 2). L1 needs to call L2. Both APIs use the database layer directly at their own nesting levels.

Now, in the database layer, I fetch the db connection from the pool each time as follows:

SqlConnection conn = new SqlConnection(connString);
conn.Open();

Is it proper to fetch the db connection each time on every DB level call as above? I know it will return a connection from the ASP.NET connection pool. However, wouldn't it be better to maintain the same DB connection throughout the nested calls (or throughout the current http request lifetime)? Will fetching a connection from the pool each time cause issues with nested TransactionScopes?