Hello, Alejandro, perhaps it is interesting for you that there is a BaseX-based open source project [1]  supporting a free mixing of node tree and file system navigation, using two different operators (/ for file system navigation, \ for node tree navigation; they can be swapped, using option -b).  Example 1: File system navigation with descendant axis and predicates: fox "samples//*[*.csv]"=>C:/Program Files/Oxygen XML Editor 19/samples/import/text Example 2: As before, predicates inspecting document contents: fox "samples//*[*.dita\learningContent]"=>C:/Program Files/Oxygen XML Editor 19/samples/dita/learning Example 3: Navigate to files, continue navigation into their content (/ followed by \): fox "samples//*.dita\*\name() => freq()"=>concept ........... (52)glossentry ........ (8)learningAssessment  (1)learningContent ... (1)learningOverview .. (2)learningPlan ...... (1)learningSummary ... (1)reference ......... (28)task .............. (64)topic ............. (67)troubleshooting ... (1) Also worth mentioning - a wealth of analytical functions complementing the navigational power, like the frequencies() function of the preceding example, or ftree-view(), presenting a tree view of selected file system resources: Example 4: Select documents and create a tree view of what has been selected: fox "samples//*.dita[\task] => ftree-view()"=><ftree context="C:/Program Files/Oxygen XML Editor 19/samples" countFo="14" countFi="64">   <fo name="dita">    <fo name="flowers">      <fo name="tasks">        <fi name="gardenPreparation.dita"/>        <fi name="pruning.dita"/>      </fo>    </fo>    <fo name="garage">      <fo name="tasks">        <fi name="carMaintenance.dita"/>        ... The examples are but the tip of an Iceberg. With kind regards -Hans-Jürgen PS: Foxpath can also navigate BaseX databases, just like file system contents, e.g. fox "basex://gidocs//*[\\*:table\\*:table]"=>basex://gidocs/gi/bmotors/678003/20210505-104638/gi_678003_gi40_20210505-104638.xmlbasex://gidocs/gi/cgear/678003/20210505-104638/gi_678003_gibook_20210505-104638.xml [1] https://github.com/hrennau/foxpath  Am Sonntag, 18. Dezember 2022 um 19:19:13 MEZ hat Alejandro Garcia <agarciafdz@gmail.com> Folgendes geschrieben: I've been reading Alexander Holupirek, 2012:Declarative Access to Filesystem Data Thesis and I think it is very interesting and very relevant today in an era of people wanting to build a "second brain". Thanks in advance