Assumptions:
From the multiple samples, only 1 sample will be used for the Regex.
As the question was about C# we would and we assume the single line, so we are using Regex.Match:
strText value like:
Robotics Automation\P-PROD\Treaghgsury\Cogre\Ignput\DaiglyCollateralggJV\03 27 2023.xlsx
strPattern as mentioned by Arjun (?<=Robotics Automation\\).*?(?=\\)