ich residuals should be extracted. By default, <code>level = 1</code>, returning both EB and LS level-1 residuals as well as marginal residuals. <code>level</code> can also be set to a grouping factor as defined in <code><a href="https://rdrr.io/r/base/names.html">names(object@flist)</a></code> in <code>lme4</code> or in <code><a href="https://rdrr.io/r/base/names.html">names(object$groups)</a></code> in <code>nlme</code>. When set to a grouping factor, <code><a href="../reference/hlm_resid.default.html">hl