This is about chainmail legwear with shoes also known as mail tights or chausses. You will get an idea about their construction.
Introduction to Chainmail Chausses
Chainmail chausses are following medieval civilian fashion. The chausses or tights worn by medieval knights are two separate pieces of chainmail armor. They are not connected like pants. Both of them are tied to a belt around the hips. Additional leather straps around the knees can help to spread the weight.
From what I have seen, chausses have the chainmail pattern always aligned with rows running around the leg. This orientation is called closed hang. The tailoring is mainly done by expansions/contractions to taper the chausses.
This type tends to have a leather sole attached permanently. Instead of the sole, there can also be an entire shoe connected to the chausses. Furthermore, it is possible to wear shoes inside the chainmail chausses, but the chainmail has a tendency to stain the leather irreversible.
To allow a tight fit, it is helpful to make a cut into the chainmail where the ankle is. This allows getting the foot into the chainmail shoes. Later that cut can be closed by a leather lace.
Chausses with an Open Backside
This version of chainmail chausses seems to have been a bit less common than the previous one. Nevertheless, it is a great choice to achieve tight-fitting chainmail chausses with a minimum of material and weight. Therefore the chausses are just a ribbon of chainmail that is tied together by a leather lace running zigzag on the backside of the leg. This type is likely worn with shoes. The chainmail is fixed to the shoes with a lace running under the sole.