diff --git a/advanced/odata.md b/advanced/odata.md
index e68b570f6e..2e5e50f7bf 100644
--- a/advanced/odata.md
+++ b/advanced/odata.md
@@ -1091,21 +1091,25 @@ If the `groupby` transformation only includes a subset of the entity keys, the r
### Transformations
-| Transformation | Description | Node.js | Java |
-|------------------------------|---------------------------------------------|:------------------:|:-----:|
-| `filter` | filter by filter expression | | |
-| `search` | filter by search term or expression | | |
-| `groupby` | group by dimensions and aggregates values | | |
-| `aggregate` | aggregate values | | |
-| `compute` | add computed properties to the result set | | |
-| `expand` | expand navigation properties | | |
-| `concat` | append additional aggregation to the result | | |
-| `skip` / `top` | paginate | | |
-| `orderby` | sort the input set | | |
-| `topcount`/`bottomcount` | retain highest/lowest _n_ values | | |
-| `toppercent`/`bottompercent` | retain highest/lowest _p_% values | | |
-| `topsum`/`bottomsum` | retain _n_ values limited by sum | | |
-
+| Transformation | Description | Node.js | Java |
+|------------------------------|----------------------------------------------|:------------------:|:-----:|
+| `filter` | filter by filter expression | | |
+| `search` | filter by search term or expression | | |
+| `groupby` | group by dimensions and aggregates values | | |
+| `aggregate` | aggregate values | | |
+| `compute` | add computed properties to the result set | | |
+| `expand` | expand navigation properties | | |
+| `concat` | append additional aggregation to the result | | |
+| `skip` / `top` | paginate | | |
+| `orderby` | sort the input set | | |
+| `topcount`/`bottomcount` | retain highest/lowest _n_ values | | |
+| `toppercent`/`bottompercent` | retain highest/lowest _p_% values | | |
+| `topsum`/`bottomsum` | retain _n_ values limited by sum | | |
+| `TopLevels` | retain only _n_ levels of a hierarchy | 2 | 1,2 |
+| `ancestors/descendants` | retain ancestors/descendants of specific nodes | 2 | 1,2 |
+
+1 - supported on SAP HANA, H2 ad PostgreSQL only
+2 - only to support requests from the UI5 Tree Table
#### `concat`
@@ -1137,7 +1141,6 @@ GET /Order(10)/books?
This query groups the 500 most expensive books by author name and determines the price of the most expensive book per author.
-
### Aggregation Methods
| Aggregation Method | Description | Node.js | Java |
@@ -1148,8 +1151,10 @@ This query groups the 500 most expensive books by author name and determines the
| `average` | average of values | | |
| `countdistinct` | count of distinct values | | |
| custom method | custom aggregation method | | |
+| custom aggregate | predefined custom aggregate | | |
| `$count` | number of instances in input set | | |
+
### Custom Aggregates
Instead of explicitly using an expression with an aggregation method in the `aggregate` transformation, the client can use a _custom aggregate_. A custom aggregate can be considered as a virtual property that aggregates the input set. It's calculated on the server side. The client doesn't know _How_ the custom aggregate is calculated.
@@ -1218,7 +1223,7 @@ A custom aggregate for a currency code or unit of measure should also be exposed
| chain transformations | | |
| chain transformations within group by | | |
| `groupby` with `rollup`/`$all` | | |
-| `$expand` result set of `$apply` | | |
+| `$expand` result set of `$apply` | | |
| `$filter`/`$search` result set | | |
| sort result set with `$orderby` | | |
| paginate result set with `$top`/`$skip` | | |