In the following, all operations are defined over a finite field of prime order. Please note that what I'm explaining below is a part of a bigger protocol, however, to keep things simple I just mention the relevant part.
Let's assume we have a secret value: $\beta$ and we want to use a one time pad to mask it as $c= \beta+r$, where $r$ is a uniformly random value.
For some reason (as a part of the bigger protocol), I need to secret share $r$ into shares: $r_1$ and $r_2$, using Shamir secret sharing scheme.
Question: given $c$ and $r_1$ can an adversary learn $r$ and ultimately $\beta$?