In this paper, we examine the interaction of $\overline{B}N$, $\overline{B}\mathrm{\Delta }$, ${\overline{B}}^{*}N$, and ${\overline{B}}^{*}\mathrm{\Delta }$ states, together with their coupled channels, by using a mapping from the light meson sector. The assumption that the heavy quarks act as spectators at the quark level automatically leads us to the results of the heavy quark spin symmetry for pion exchange and reproduces the results of the Weinberg Tomozawa term, coming from light vector exchanges in the extended local hidden gauge approach. With this dynamics we look for states dynamically generated from the interaction and find two states with nearly zero width, which we associate to the ${\mathrm{\Lambda }}_b(5912)$ and ${\mathrm{\Lambda }}_b(5920)$ states. The states couple mostly to ${\overline{B}}^{*}N$, which are degenerate with the Weinberg Tomozawa interaction. The difference of masses between these two states, with $J=1/2$ and $3/2$, respectively, is due to pion exchange connecting these states to intermediate $\overline{B}N$ states. In addition to these two ${\mathrm{\Lambda }}_b$ states, we find three more states with $I=0$, one of them nearly degenerate in two states of $J=1/2$, $3/2$. Furthermore, we also find eight more states in $I=1$, two of them degenerate in $J=1/2$, $3/2$, and another two degenerate in $J=1/2$, $3/2$, $5/2$.

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