This is the 10804th most frequent Russian word.
выбравшие
"Those who have chosen."
In this sentence, 'выбравшие' functions as the past participle used as part of a noun phrase, referring to people who have made a choice.
Те, кто выбравшие этот путь, знают его сложности.
Those who have chosen this path know its difficulties.
Here, 'выбравшие' is used as an adjective-like participle describing the people who made the choice of the medical profession.
Выбравшие профессию врача достойны уважения.
Those who have chosen the profession of a doctor deserve respect.
'выбравшие' in this sentence is a participle introducing additional information about the students, specifically qualifying them.