There are some excellent videos available on Youtube from Jazz at Lincoln Center’s JAZZ ACADEMY for all instrumentalists. Here is a collection of videos specifically aimed at Rhythm Section players in a Big Band.
Rhythm Section as a whole
How to Tie Together a Big Band Rhythm Section
When Big Bands Were Dance Bands
What Does a Rhythm Section Do in Jazz
Jazz Fundamentals: What is Swing?
Bass
Playing Bass in a Big Band
Some great videos on how to construct your own walking lines from chord symbols
Introduction to the Walking Bass, Part One
Tips for Building Your Walking Bass
Bassists: You Need to Practice Rhythm Changes
Guitar
Jazz Guitar Comping in the Style of Freddie Green
Electric Guitar Setup for Big Band Jazz
How to Develop Good Rhythm on Jazz Guitar
How to Play Jazz Chords, Part One
Drums
Connecting the Bass and the Drums: The Ride Cymbal and Walking Bass
The Reverse Feather on the Bass Drum
How to Stay Loose on the Drums
How to Develop Triplet Independence on the Drums
Piano
What Does a Rhythm Section Do in Jazz
Other non-rhythm section videos relating to Big Band specifically
The role of Lead Alto in a Big Band