The first article at the link below talks about that the Bi-Directional Grid Constrained (BGC) stochastic processes for a random variable X over time t is one in which the further it departs from the origin, then the further it will be constrained from above and below (bi-directionally) along that X dimension (see section "Definition 1.1. Bi-Directional Grid Constrained (BGC) Stochastic Process").
Section 5 (Conclusion) states "The net effect of the BGC operates as a reflecting horizontal hidden barrier, from which we derived a theorem for the logarithmic bounds of the resulting envelope."
QUESTION: I would like to know how to determine the boundary level at which the random variable X is constrained?
Article - ITERATED LOGARITHM BOUNDS OF BI-DIRECTIONAL GRID CONSTRAINED STOCHASTIC PROCESSES
There is a related article found here which may also add some background BI-DIRECTIONAL GRID CONSTRAINED STOCHASTIC PROCESSES' LINK TO MULTI-SKEW BROWNIAN MOTION