How to list the contents of a folder in a tree-like fashion in Linux

Use the tree command:

cd /sw/oracle/admin
tree -L 2
.
├── cdb
│   ├── adump
│   ├── dpdump
│   ├── log
│   ├── pfile
│   └── xdb_wallet
├── sales
│   ├── adump
│   ├── dpdump
│   ├── pfile
│   ├── sql
│   └── xdb_wallet
└── hr
    ├── adump
    ├── dpdump
    ├── log
    ├── pfile
    ├── scripts
    ├── sql
    └── xdb_wallet

20 directories, 0 files

The -L flag indicates the number of levels you want to display. In my case, if I change the value from 2 to 3, I get the output below instead (abbreviated):

.
├── cdb
│   ├── adump
│   │   ├── FE78BD1F8E6730CDE0536709D10AC9C0
│   │   └── FE7BD04D2DFBE569E0536709D10A3AF0
│   ├── dpdump
│   │   ├── dp.log
│   │   ├── FE78BD1F8E6730CDE0536709D10AC9C0
│   │   ├── FE7AF28B415262F7E0536709D10A8B2E
│   │   └── FE7BD04D2DFBE569E0536709D10A3AF0
│   ├── log
│   │   ├── 2023-07-11_cdb.2431565
│   │   ├── 2023-07-12_cdb.2489915
│   │   ├── 2023-07-12_cdb.2576176
├── sales
│   ├── adump
│   ├── dpdump
│   │   └── dp.log
│   ├── pfile
│   │   └── init.ora.5192023145034
│   ├── sql
│   │   ├── analyze_sales.sh
│   │   ├── cfgtoollogs
│   │   ├── config_sales.txt
│   │   ├── cre_db.sh
│   │   └── deploy_sales.sh

26 directories, 181 files

The command is not installed by default but is avaible both for RHEL / CentOS / Fedora Linux as well as Debian based Linux distributions like Ubuntu.