I understand de Casteljau's algorithm and I am familiar although not fully experienced with B-Splines. I am trying to understand the geometric interpretation of B-splines through the algorithm (just like how de Casteljau's algorithm shows the geometric interpretation of Bézier curves). Thank you in advance.
What you're looking for is called de Boor's algorithm. It lets you compute a point on a b-spline curve by doing a series of linear interpolation (LERP) calculations. So, it works very much like the de Casteljau algorithm for Bezier curves. In fact, the de Casteljau algorithm is a special case of de Boor's algorithm.