Metafor - rma.mv function - variance components

Hi all,

I have a question about metafor and the rma.mv function. I have fitted a multivariate model (effect sizes are nested within studies) and I've found two variances: 

Variance Components: 
                      estim    sqrt     nlvls  fixed  factor
sigma^2.1  0.0257  0.1602     72     no       y
sigma^2.2  0.0694  0.2635     10     no      ID 

I want to test whether there is significant variantion between the effect sizes within studies (sigma^2.1: 0.0257) and/or between studies (sigma^2.2: 0.0694). In metaSEM you can fix for example the variance within studies (sigma^2.1) to zero to test whether there is a significant difference in fit between the models (and if so, then there is significant heterogeneity between the effect sizes within studies). I was wondering if this is also possible in metafor. If I fix sigma2 to zero, then both variances are fixed to zero. However, I want to fix only one variance to zero. 
I hope that someone can help me. Thank you in advance!