From BioStar v2.7.5, Active Directory Synchronization is supported.
Refer to the below link.
If you're looking for a way to simply export users from Active Directory and import it to BioStar 2, you do not need to integrate BioStar with Active Directory, you would simply have to export the users from Active Directory as a CSV file and import it.
You can find solutions online to export users out of Active Directory into a csv file.
Below is a sample solution found on Microsoft Technet:
Powershell Script to export Active Directory users to CSV (external link)
Warning: this solution has not been tested and we cannot provide any guarantee or support for this script
You can import users into BioStar 2 following the steps shown in Knowledgebase below: